Effect of angiotensin II type 1 receptor antibodies on graft function and survival in paediatric kidney transplant recipients.

HLA donor specific antibodies (DSA) are implicated in antibody-mediated rejection (AMR), graft dysfunction and failure in kidney transplant (KT) recipients. Non-HLA antibodies including angiotensin II type 1 receptor (AT1R) may also play a role in AMR, impact graft function and survival. Data is limited in paediatric KT cohorts. We aimed to assess the prevalence and effect of pre-transplant AT1R antibodies on rejection, graft function and survival in paediatric KT recipients. This was a retrospective cohort study conducted across two paediatric centres including KT recipients with a pre-transplant AT1R antibody level. Outcomes included rejection, de novo DSA formation, graft function, failure, proteinuria and hypertension. Of 71 individuals, 72% recorded a positive pre-transplant AT1R Ab level (≥17 U/mL). Over a median follow-up of 4.7 years, AT1R Ab positivity demonstrated a trend towards increased risk of rejection however was not statistically significant (HR 3.45, 95% CI 0.97-12.35, p-value 0.06). Sensitivity analysis with AT1R Ab levels of ≥25 U/mL (HR 2.05 95% CI 0.78-5.39, p-value 0.14) and ≥40 U/mL (HR 1.32, CI 95% 0.55-3.17, p-value 0.53) validated this. De novo DSA formation occurred more frequently with AT1R Ab positivity (41% vs. 20%, p-value 0.9). AT1R Ab was not associated with hypertension, proteinuria, graft failure or dysfunction. In conclusion, this cohort study demonstrated a high prevalence of pre-transplant AT1R Ab positivity (72%). AT1R Ab positivity demonstrated a trend towards increased risk of rejection and de novo DSA formation however did not meet statistical significance. There was no association between AT1R Ab and hypertension, proteinuria, graft failure or dysfunction.

Cause of intrauterine and neonatal death in twin pregnancies (CoDiT): development of a novel classification system.

OBJECTIVE: Twin pregnancies have a significantly higher perinatal mortality than singleton pregnancies. Current classification systems for perinatal death lack twin-specific categories, potentially leading to loss of important information regarding cause of death. We introduce and test a classification system designed to assign a cause of death in twin pregnancies (CoDiT). DESIGN: Retrospective cross-sectional study. SETTING: Tertiary maternity unit in England with a perinatal pathology service. POPULATION: Twin pregnancies in the West Midlands affected by fetal or neonatal demise of one or both twins between 1 January 2005 and 31 December 2016 in which postmortem examination was undertaken. METHODS: A multidisciplinary panel designed CoDiT by adapting the most appropriate elements of singleton classification systems. The system was tested by assigning cause of death in 265 fetal and neonatal deaths from 144 twin pregnancies. Cause of death was validated by another obstetrician blinded to the original classification. MAIN OUTCOME MEASURES: Inter-rater, intra-rater, inter-disciplinary agreement and cause of death. RESULTS: Cohen's Kappa demonstrated 'strong' (>0.8) inter-rater, intra-rater and inter-disciplinary agreement (95% CI 0.70-0.91). The commonest cause of death irrespective of chorionicity was the placenta; twin-to-twin transfusion syndrome (TTTS) was the commonest placental cause in monochorionic twins and acute chorioamnionitis in dichorionic twins. CONCLUSIONS: This novel classification system records causes of death in twin pregnancies from postmortem reports with high inter-user agreement. We highlight differences in aetiology of death between monochorionic and dichorionic twins. TWEETABLE ABSTRACT: New classification system for #twin cause of death 'CoDiT' shows high rater agreement.

Pregnancy outcomes in women with primary biliary cholangitis and primary sclerosing cholangitis: a retrospective cohort study.

OBJECTIVE: To determine maternal, obstetric and neonatal outcomes in a cohort of women with primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC). DESIGN: Retrospective cohort study. SETTING: Ten specialist centres managing pregnant women with liver disease. POPULATION: Women with a diagnosis of PBC and PSC and a pregnancy of ≥20 completed weeks of gestation. METHODS: Retrospective case notes review. MAIN OUTCOME MEASURES: Adverse outcomes were defined as: maternal - development of ascites, variceal bleeding, encephalopathy and jaundice; obstetric events - gestational hypertension, pre-eclampsia and postpartum haemorrhage; and neonatal - stillbirth, preterm delivery and admission to neonatal unit. The relationship of alanine transferase (ALT) and bile acid levels with gestation at delivery was studied. RESULTS: The first recorded pregnancies of 34 women with PSC and 27 women with PBC were analysed. There were 60 live births and one intrapartum stillbirth that did not occur in the context of maternal cholestasis. The overall median gestation of delivery was 38 weeks but the rate of preterm birth was 28% (17/61 deliveries), 76% (13/17) of which were spontaneous. Gestation at birth negatively correlated with maternal serum ALT concentration at booking (P = 0.017) and serum bile acid concentration during pregnancy (P = 0.016). There were no other significant correlations and maternal and neonatal outcomes were good. CONCLUSIONS: Pregnancy in PBC and PSC is well tolerated, but women should be counselled regarding the increased risk of preterm birth. Measurement of maternal ALT and bile acids may help identify women at risk of preterm delivery. TWEETABLE ABSTRACT: Pregnancy in women with PBC and PSC is well tolerated; however, rates of preterm birth are high and are related to maternal bile acid levels.

Prognosis of the co-twin following spontaneous single intrauterine fetal death in twin pregnancies: a systematic review and meta-analysis.

BACKGROUND: Single intrauterine fetal death affects approximately 6% of twin pregnancies and can have serious sequelae for the surviving co-twin. OBJECTIVES: Determine the prognosis of the surviving co-twin following spontaneous single intrauterine fetal death to aid counselling patients and highlight future research areas. SEARCH STRATEGY: Medline, Embase, Web of Science, and Cochrane Library, from 1980 to June 2017. SELECTION CRITERIA: Studies of five or more cases of spontaneous single intrauterine fetal death after 14 weeks gestation, in diamniotic twin pregnancies. DATA COLLECTION AND ANALYSIS: Summary event rates were calculated and stratified by chorionicity. Monochorionic and dichorionic twins, and sub-groups, were compared by odds ratios. MAIN RESULTS: In monochorionic twins, when single intrauterine fetal death occurred at less than 28 weeks' gestation, this significantly increased the rate of co-twin intrauterine fetal death [odds ratio (OR) 2.31, 95% confidence interval (CI) 1.02-5.25, I2  = 0.0%, 12 studies, 184 pregnancies] and neonatal death (OR 2.84, 95% CI 1.18-6.77, I2  = 0.0%, 10 studies, 117 pregnancies) compared with when the single intrauterine fetal death occurred at more than 28 weeks' gestation. Neonatal death in monochorionic twins was significantly higher if the pregnancy was complicated by fetal growth restriction (OR 4.83, 95% CI 1.14-20.47, I2  = 0.0%, six studies, 60 pregnancies) or preterm birth (OR 4.95, 95% CI 1.71-14.30, I2  = 0.0%, 11 studies, 124 pregnancies). Abnormal antenatal brain imaging was reported in 20.0% (95% CI 12.8-31.1, I2  = 21.9%, six studies, 116 pregnancies) of surviving monochorionic co-twins. The studies included in the meta-analysis demonstrated small study effects and possible selection bias. CONCLUSIONS: Preterm birth was the commonest adverse outcome affecting 58.5 and 53.7% of monochorionic and dichorionic twin pregnancies. Outcomes regarding brain imaging and neurodevelopmental comorbidity are an important area for future research, but meta-analysis may be limited due to different methods of assessment. TWEETABLE ABSTRACT: Preterm birth is the highest risk in single co-twin death. Abnormal antenatal brain imaging was found in 1/5 surviving MC twins.

The accuracy of cell-free fetal DNA-based non-invasive prenatal testing in singleton pregnancies: a systematic review and bivariate meta-analysis.

BACKGROUND: Cell-free fetal DNA (cffDNA) non-invasive prenatal testing (NIPT) is rapidly expanding, and is being introduced at varying rates depending on country and condition. OBJECTIVES: Determine accuracy of cffDNA-based NIPT for all conditions. Evaluate influence of other factors on test performance. SEARCH STRATEGY: Medline, Embase, CINAHL, Cochrane Library, from 1997 to April 2015. SELECTION CRITERIA: Cohort studies reporting cffDNA-based NIPT performance in singleton pregnancies. DATA COLLECTION AND ANALYSIS: Bivariate or univariate meta-analysis and subgroup analysis performed to explore influence of test type and population risk. MAIN RESULTS: A total of 117 studies were included that analysed 18 conditions. Bivariate meta-analysis demonstrated sensitivities and specificities, respectively, for: fetal sex, 0.989 (95% CI 0.980-0.994) and 0.996 (95% CI 0.989-0.998), 11 179 tests; rhesus D, 0.993 (95% CI 0.982-0.997) and 0.984 (95% CI 0.964-0.993), 10 290 tests; trisomy 21, 0.994 (95% CI 0.983-0.998) and 0.999 (95% CI 0.999-1.000), 148 344 tests; trisomy 18, 0.977 (95% CI 0.952-0.989) and 0.999 (95% CI 0.998-1.000), 146 940 tests; monosomy X, 0.929 (95% CI 0.741-0.984) and 0.999 (95% CI 0.995-0.999), 6712 tests. Trisomy 13 was analysed by univariate meta-analysis, with a summary sensitivity of 0.906 (95% CI 0.823-0.958) and specificity of 1.00 (95% CI 0.999-0.100), from 134 691 tests. False and inconclusive results were poorly reported across all conditions. Although the test type affected both sensitivity and specificity, there was no evidence that population risk had any effect. CONCLUSION: Performance of cffDNA-based NIPT is affected by condition under investigation. For fetal sex and rhesus D status, NIPT can be considered diagnostic. For trisomy 21, 18, and 13, the lower sensitivity, specificity, and disease prevalence, combined with the biological influence of confined placental mosaicism, designates it a screening test. These factors must be considered when counselling patients and assessing the cost of introduction into routine care. TWEETABLE ABSTRACT: cffDNA NIPT accuracy high, can be diagnostic for fetal sex and rhesus D, but only screening test in aneuploidy.

The national incidence and clinical picture of SLE in children in Australia - a report from the Australian Paediatric Surveillance Unit.

OBJECTIVES: The objectives of this paper are to prospectively determine the incidence of paediatric systemic lupus erythematosus (pSLE) in Australia as well as describe the demographics, clinical presentation and one-year outcome. STUDY DESIGN: Newly diagnosed cases of pSLE were ascertained prospectively from October 2009 to October 2011 through the Australian Paediatric Surveillance Unit (a national monthly surveillance scheme for notification of childhood rare diseases) as well as national subspecialty groups. Questionnaires were sent to notifying physicians at presentation and at one year. RESULTS: The annual incidence rate was 0.32 per 10(5) children aged less than 16 years. The incidence was significantly higher in children of Asian or Australian Aboriginal and Torres Strait Islander parents. Approximately one-third of children underwent a renal biopsy at presentation and 7% required dialysis initially although only one child had end-stage kidney disease (ESKD) at one-year follow-up. CONCLUSION: The incidence of pSLE in Australia is comparable to that worldwide with a significantly higher incidence seen in children of Asian and Australian Aboriginal and Torres Strait Islander backgrounds. Renal involvement is common but progression to ESKD, at least in the short term, is rare.

Safety and adequacy of percutaneous biopsies in pediatric orthotopic kidney transplantation.

BACKGROUND: The gold standard for investigating the cause of renal graft dysfunction is renal biopsy. However, as this procedure is invasive and has inherent risks, its safety must be established. OBJECTIVE: To determine the safety of percutaneous renal biopsy in pediatric orthotopic renal transplantation. METHODS: Percutaneous renal biopsies performed on pediatric orthotopic renal transplants in a single center between 1987 and 2010 were studied. Biopsy specimen adequacy and post-procedure complications were reviewed by prospectively collected data. RESULTS: A total of 54 ultrasound "real-time" guided biopsies in 25 patients were performed. Minimum specimen adequacy was achieved in 98% of biopsy specimens. No major complications were identified; 6% of patients developed minor complications-e.g., grade 3 macroscopic hematuria that did not require intervention. CONCLUSION: Percutaneous renal biopsies using "real-time" ultrasound guidance on pediatric orthotopic kidney transplants is safe.

BK viral infection in an Australian pediatric renal transplant population.

BK virus (BKV) is recognized as a significant cause of renal allograft dysfunction in adults, and there is growing awareness of its importance in the pediatric population. Eighteen pediatric renal transplant recipients and 18 age-matched controls were prospectively studied. Anti-BKV immunoglobulin G (IgG) and IgM titres were assayed in all subjects at entry to the study. Polymerase chain reaction (PCR) for BKV DNA was performed on urine and serum at entry, and prospectively tested again at 4, 8 and 12 months. Mean age +/- s.d. of transplant recipients and controls was 14.6 +/- 3.3 and 13.9 +/- 0.33 yr respectively [not significant (NS)]. Transplant patients were studied at a mean time of 5.6 +/- 4.2 yr post-transplant. 56% of transplant patients and 39% of controls were seropositive (+ve BKV IgG) (NS). Plasma BKV PCR was positive in one transplant patient (who also had positive urine PCR) and in none of the controls. The prevalence of positive urine PCR in transplant patients was greater than in controls (33% vs. 0%, p = 0.02). Positive urine BKV PCR was more commonly found in patients treated with mycophenolate than azathioprine (p = 0.04). We conclude that the prevalence of BKV seropositivity and viral activation in this Australian pediatric renal transplant population is similar to that reported in adult and pediatric populations in other countries. BK viruria was more common in children with greater immunosuppression, suggesting that this group is at higher risk of BKV induced nephropathy.

Recombinant factor VIIa used to control massive haemorrhage during renal transplantation surgery; vascular graft remained patent.

There is a growing body of evidence to support the use of rFVIIa in cases of excessive bleeding outside its approved use in haemophilia with inhibitors. We now report its use for a paediatric renal transplant case in which its use was both life saving and did not threaten the vascular grafts. To our knowledge this represents the first reported case of rFVIIa used in the setting of renal transplantation. It is reassuring that despite use of a high dose of rFVIIa (>135 mcg/kg; recommended standard dose is 90 mcg/kg) there was no evidence of anastomotic thrombosis.

Intrarenal angiotensin and bradykinin peptide levels in the remnant kidney model of renal insufficiency.

BACKGROUND: The remnant kidney model of renal failure is associated with normal or suppressed plasma renin and angiotensin (Ang) II levels when hypertension is established. However, the hypertension responds to angiotensin-converting enzyme (ACE) inhibition and Ang II receptor antagonism, suggesting a role for Ang II in the hypertensive process. Bradykinin (BK) is a potent vasoactive peptide that may also participate in this model. METHODS: Ang II and BK peptides were measured in the ischemic peri-infarct portion and the intact portion of the remnant kidney at two, five, and seven weeks after surgery. Plasma Ang II, renin, angiotensinogen, and aldosterone levels were also measured. RESULTS: Ang II levels in the peri-infarct portion were higher than in the intact portion at all time points and were higher than in sham-operated kidney at two weeks. Ang II levels in the intact portion were similar to the levels in kidneys of sham-operated rats at two and five weeks and were suppressed at seven weeks. BK levels were increased in the peri-infarct portion at all time points and in the intact portion at two and five weeks. Plasma Ang II and aldosterone levels were also elevated at two weeks. CONCLUSIONS: Peri-infarct renal tissue Ang II levels and plasma Ang II and aldosterone levels increase transiently during the evolution of hypertension in the remnant kidney model. Sustained hypertension is associated with an increase in intrarenal BK levels but not with persistent increases in intrarenal or circulating Ang II levels.

Pulmonary capillary leak syndrome with intravenous cyclosporin A in pediatric renal transplantation.

Despite frequent use of intravenous (i.v.) cyclosporin A (CsA) in the early post-operative course of transplant recipients, allergic reactions have been infrequently described. Of 134 transplants, we report four pediatric renal transplant recipients with severe reaction to i.v. CsA with pulmonary capillary leak syndrome. Pulmonary edema developed at a mean time of 3.5 h after commencement of i.v. CsA, with two patients requiring mechanical ventilation. Discontinuation of i.v. CsA and conversion to oral CsA was followed by rapid resolution of pulmonary edema, suggesting that cremaphor, the solubilizing agent in the i.v. formulation, is likely to be responsible for this adverse response. Skin prick testing with cremaphor was negative in all patients and alternative mechanisms for the cremaphor response are proposed. It is likely that inadequate mixing of the i.v. CsA solution triggered this reaction, by delivering a higher concentration of cremaphor at the start of the CsA infusion. Pulmonary edema in the early post-transplant course in the absence of obvious fluid overload should prompt the diagnosis of an i.v. CsA reaction. This life-threatening reaction is easily reversible if recognized, and can be managed easily without compromise to the allograft, by discontinuing i.v. CsA and switching early to an oral CsA formulation.

Successful transplantation of adult-sized kidneys into infants requires maintenance of high aortic blood flow.

BACKGROUND: Nationally, results of renal transplantation in infants are inferior to those in older children and adults. Within the infant group, best results are obtained with adult-sized kidneys (ASKs) rather than size-compatible pediatric kidneys. However, transplantation of ASKs into infants has an increased risk of acute tubular necrosis and graft loss from vascular thrombosis and primary nonfunction. The aim of this study was to define and understand the hemodynamic changes induced by ASK transplantation, so that outcomes of transplantation in infants can be improved. METHODS: Nine hemodynamically stable and optimally hydrated infants were studied under a controlled sedation with cine phase-contrast magnetic resonance at three time periods: before transplantation, 8-12 days after transplantation, and 4-6 months after transplantation. Cross-sectional images of both the infant aorta and the adult transplant renal artery were obtained and blood flow was quantitated. Renal volumes were also obtained, and expected renal artery blood flow based on early posttransplant volume was calculated. In addition, renal artery blood flow was determined in 10 in situ native adult kidneys prior to donor nephrectomy. Supplemental nasogastric or gastrostomy tube feeding was carried out during the blood flow study period to optimize intravascular volume. RESULTS: Mean infant aortic blood flows were 331+/-148 ml/min before transplantation, 761+/-272 ml/ min at 8-12 days after transplantation (P=0.0006 with pretransplant flow), and 665+/-138 ml/min at 4-6 months after transplantation (P=0.0001 with pretransplant flow). Mean transplanted renal artery flows were 385+/-158 ml/min at 8-12 days and 296+/-113 ml/min at 4-6 months after transplantation. Transplanted renal artery flows were less than prenephrectomy in situ donor renal artery blood flow (618+/-130 ml/min; P=0.02 and P=0.0003) and expected normal renal artery blood flow (666+/-87 ml/min; P=0.003 and P=0.001) at both 8-12 days and 4-6 months after transplantation. A 26% reduction in renal volume (P=0.003) occurred between the two postoperative time periods, and this paralleled the decrease in posttransplant renal artery flow. One-year graft and patient survival in the nine infants was 100%. The mean serum creatinine levels at 3, 6, and 12 months were 0.43+/-0.10, 0.48+/-0.15, and 0.49+/-0.16 mg/dl. CONCLUSIONS: This study is the first to quantitatively document the blood flow changes occurring after ASK transplantation in infants. There was a greater than two-fold increase in aortic blood flow after ASK transplantation, and this increase was sustained for at least 4 months and appeared to be driven by the blood flow demand of the ASK. However, actual posttransplant renal artery blood flow was significantly less than normal renal artery flow. Our study suggests that aggressive intravascular volume maintenance may be necessary to achieve and maintain optimum aortic blood flow, so as not to further compromise posttransplant renal artery flow and to avoid low-flow states that could induce acute tubular necrosis, vascular thrombosis, or primary nonfunction.

Neonatal Bartter syndrome--use of indomethacin in the newborn period and prevention of growth failure.

Neonatal Bartter syndrome differs from the classical Bartter syndrome in the occurrence of antenatal presentation with polyhydramnios. Nephrocalcinosis and severe growth retardation are common sequelae. Indomethacin has been reported to improve linear growth, but its use in the early newborn period has been infrequently described. In this paper we report normal growth and development and the absence of nephrocalcinosis in an infant now aged 19 months with neonatal Bartter syndrome treated from day 3 of life with indomethacin. With early diagnosis and treatment with indomethacin plus adequate water, calories, and sodium, normal growth can be achieved and nephrocalcinosis may be prevented in children with neonatal Bartter syndrome.

Primary and secondary liver/kidney microsomal autoantibody response following infection with hepatitis C virus.

Liver/kidney microsomal autoantibody type 1 (LKM-1), which characterizes a subtype of autoimmune hepatitis, is also found in some patients with chronic hepatitis C virus (HCV) infection. Whether HCV and LKM-1 are accidentally or causally related is unknown. This case report describes a child who became infected by HCV after liver transplantation for end-stage liver disease caused by alpha 1-antitrypsin deficiency. LKM-1 was detected by immunofluorescence, anti-microsomal reactivity by Western blotting, anti-HCV and anti-GOR by immunoenzymatic assays, and HCV RNA by polymerase chain reaction. Two weeks after HCV infection, immunoglobulin (Ig) M LKM-1 appeared, followed by IgG1 LKM-1, with titers increasing to 1/2560; antibodies to a 50-kilodalton liver microsomal protein appeared 2 months later. Sera from day 1 posttransplant became positive for HCV RNA. HCV RNA was also detected in a liver biopsy specimen obtained 3 months after surgery. The patient did not produce anti-HCV and anti-GOR antibodies throughout the study and had no histological evidence of hepatitis. The temporal relationship between HCV infection and LKM-1 production suggests that HCV may trigger a primary autoimmune response. The lack of liver damage attributable to autoimmunity or viral infection may be caused by immunosuppression.